The present invention is concerned with a machine including a base adapted to have mounted thereon a printer, and improved structure for diagnosing malfunctions in and adjusting drive systems and control structures therefor.
This application is related to the following four, U.S. patent applications concurrently filed by A. Eckert, Jr. et. al., Feb. 25, 1992, and assigned to the assignee of the present invention: Ser. No. 07/841,911 for Mailing Machine Including Sheet Feeding Speed Calibrating Means; Ser. No. 07/724,304 for Mailing Machine Including Printing Speed Calibrating Means; Ser. No. 07/841,915 for Mailing Machine Including Skewed Sheet Detection Means and Ser. No. 07/841,912 for Mailing Machine Including Short Sheet Length Detecting Means.
As shown in U.S. Pat. No. 4,774,446, for a Microprocessor Controlled D.C. Motor For Controlling Printing Means, issued Sep. 27, 1988 to Salazar, et. al. and assigned to the assignee of the present invention, there is described a mailing machine which includes a closed loop, sampled data, feed back control system for continuously matching the peripheral speed of a postage printing drum to the feeding speed of a sheet.
As shown in U.S. Pat. No. 4,864,505 for a Postage Meter Drive System, issued Sep. 5, 1989 to Miller, et. al. and assigned to the assignee of the present invention, there is described a mailing machine including three separate motors for driving the sheet feeding, shutter bar moving and postage printing drum driving structures
As shown in U.S. Pat. No. 4,787,311, for a Mailing Machine Envelope Transport System, issued Nov. 29, 1988 to Hans C. Mol and assigned to the assignee of the present invention, there is disclosed a microprocessor driven stepper motor in a mailing machine base for driving a postage printing drum at a peripheral speed which matches the speed of a sheet fed therebeneath.
As shown in U.S. Pat. No. 4,639,918 for a Diagnostic Keyboard For a Mailing Machine, issued Jan. 27, 1987 to Linkowski and assigned to the assignee of the present invention, it is known in the art to provide a mailing machine which includes a microcomputer for controlling structures for feeding a sheet downstream in a path of travel and printing postage indicia on the sheet, and which includes a sensor for sensing the leading edge of a sheet fed through the machine, wherein the microprocessor is programmed to respond to a signal from the sensor to delay indicia printing for a predetermined time interval to locate the postage indicia a predetermined distance upstream from the leading edge of the sheet. Further, as shown in the '918 patent, it is known in the art to connect a plurality of selectively manually actuatable switches to the microprocessor and program the microprocessor to respond to actuation of one or more of the switches to select one of a plurality of different delay time intervals for locating the postage indicia different distances from the leading edge of a sheet. And, as shown in the ' 918 patent it is known in the art to provide a mailing machine control panel which includes a plurality of machine operating keys which are normally selectively actuatable for operating the mailing machine in a sheet processing mode, but, in response to depressing a separate test key, which switches the machine to a test mode of operation, the keys are selectively actuatable for implementing a variety of diagnostic test routines.
Accordingly:
an object of the invention is to provide improved apparatus for testing sheet feeding and printing drum drive systems in a machine; PA1 another object provide a machine including automatic sensor testing structure; PA1 another object is to provide improved structure for selecting adjusting the marginal distance from the leading edge of a sheet at which indicia is to be printed thereon; PA1 another object of the invention is to provide an improved, low cost, low operational noise level, machine including structure for accounting for malfunction conditions; PA1 another object is to provide improved microprocessor controlled sheet feeding, shutter bar moving and postage printing drum driving structures in a mailing machine base including structure for storing data corresponding to malfunctions; PA1 another object is to provide a microprocessor controlled d.c. motor for timely accelerating a postage meter drum from rest, in its home position, to a substantially constant velocity, maintaining the velocity constant, decelerating the drum from constant velocity to rest in its home position and storing an error code if during such drum movement the drum does not timely transition to and from the constant velocity thereof; PA1 another object is to provide a method and apparatus for detecting skewed sheets fed to a mailing machine base and storing an error code corresponding thereto; PA1 another object is to provide a method and apparatus for detecting sheets of insufficient length fed to a mailing machine for printing postage indicia thereon and storing an error code corresponding thereto; PA1 another object is to provide structure for accounting for malfunction conditions indicating unacceptable differences between actual and desired movements of components of a mailing machine base and a sheet fed thereby; PA1 another object is to provide structure utilized for displaying current and historical error conditions, and alternatively, displaying each of a plurality of selected marginal distances of displacement from the leading edge of a sheet at which postage indicia is printed, and PA1 another object is to provide structure for automatically testing the condition of various sensors in a mailing machine base in response to energization thereof and storing an error code corresponding to each malfunction condition found in the course of such testing.